Which box do you have, the TV Hub or the 4k Netgem Box?
Have you tried a reset of the box? This will download the box software again and if it's a bug will hopefully solve this.
From the 29th of March our TalkTalk Community will move to peer-to-peer support and the TalkTalk team will no longer be here to support with queries. Don’t worry we still have plenty of ways to reach out if you need to speak to TalkTalk directly. For more details check out the link here:
How to contact TalkTalk Broadband - Help & Support.
